'Open source' generally gets read to mean 'available under an OSI or OSI-like license', and 'free software' as 'available under the GPL or a GPL-like license' IME - if the license is commercial only but the code's still freely -readable- albeit not freely -runnable- then 'source available' is clearer.
(note that sqs clarifies elsewhere in the thread that 'open source' was being used to refer to the stuff that's (still) Apache 2 licensed, not the source available parts)
Free software is largely coterminous with open source. Even Stallman uses the term 'copylefted software' to refer to software under a so-called copyleft license -- one which, like the GPL, forbids license changes upon redistribution. Stallman will tell you that he'd rather your free software be copylefted, but it doesn't have to be.
You're right about source-available though. It's what we used to call 'shared source', after a failed attempt by Microsoft to promote that as an alternative to the viral, cancer-like open source.
